So, in parallel, amazon doesn't really give a crap about whether they sell a ton of kindles. What they care about is that the amazon kindle store makes a crap-ton of money. If everyone goes out and buys an ipad, and "kindle on ipad" is a killer app for ipad, amazon ends up making way more money than they would trying to match their own hardware against Apple's.
I'm an avid reader and I got the DX when it came out (it is freaking sweet). I'd probably be too distracted/eye-strained reading on a tablet PC for the number of hours that I do. (I realize that I am an outlier, however).
My one complaint is that there are actually a lot of books that I cannot get for the kindle, and it is hard to take notes in the margin so I end up reading certain books on dead trees. (Maybe the ipad touch screen will make it easier to do margin notes?)